Solar Coronal Holes

Solar Coronal Holes Latest News

Recently, a new study has accurately estimated the physical parameters of thermal and magnetic field structures of solar coronal holes.

About Solar Coronal Holes

• Coronal holes are dark regions in X-ray and extreme ultraviolet images of the Sun.
• These were discovered in the 1970s by X-ray satellites.

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Features of Solar Coronal Holes

• They appear dark because they are cooler, less dense regions than the surrounding plasma and are regions of open, unipolar magnetic fields. 
• They have open magnetic field lines and are hence important for understanding the interplanetary medium and space weather.
• Coronal holes can last between a few weeks to months. The holes are not a unique phenomenon, appearing throughout the sun’s approximately 11-year solar cycle.
• They can last much longer during solar minimum – a period of time when activity on the Sun is substantially diminished, according to NASA.

Significance of Solar Coronal Holes

• The occurrences of coronal holes are associated with disturbances in the Earth’s ionosphere, the layer of the atmosphere that reflects and modifies the radio waves, leading to further communication issues.
• They have significant influence on space weather that affects satellites, as well as the Indian summer monsoon rainfall.

Solar Coronal Holes FAQs

Q1. What is a solar coronal hole?

Ans. A coronal hole is a large region in the corona which is less dense and is cooler than its surroundings.

Q2. What is ejected from the Sun’s coronal hole?

Ans. Coronal mass ejections (CMEs) are huge bubbles of coronal plasma threaded by intense magnetic field lines that are ejected from the Sun over the course of several hours.

Q3. Why do sunspots appear dark?

Ans. Sunspots are areas that appear dark on the surface of the Sun. They appear dark because they are cooler than other parts of the Sun’s surface.

Source: PIB